You will need to speak to your insurance company to get the specifics about your policy and the insurance carriers guidelines but typically you would only be able to put a claim through your uninsured motorist policy.

An underinsured motorist would mean that the other driver had insurance but the coverage was not sufficient to fairly compensate you for your injuries. Instead you had an uninsured motorist, meaning he did not have auto insurance of any type, hit you and thus that would be the coverage used.

If you live in a state that requires personal injury protection (PIP), that coverage would generally be used first and then the uninsured motorist coverage would be secondary. Uninsured motorist does typically allow you to collect for lost wages and pain and suffering if it is so stated in the terms of your policy.